SI B24 02 12 did not work for me. See email below, which resulted in a productive exchange with an excellent Gault BMW customer service rep (Dave Belknapp) and a BMW field engineering rep. The more current service bulletin SI B12 09 12 was performed. I took our car on an urban road trip and the throttle now acts more like a mechanical linkage...no more 'requests to the department of engines and transmissions for consideration of acceleration needs'. In my opinion, the Nov 2012 fix described in the attached bulletin SI B12 09 12 works indeed!

My wife and I love many aspects of our 2011 X3 35i. We had an absolute blast at the Performance Center Delivery in the Fall of 2011!

There is a significant, persistent issue that has not been resolved to our satisfaction, despite 2 service appointments. Throttle behavior at low speed is unpredictable and erratic to a degree that it keeps me on edge. My wife now looks for reasons to not drive the car. It is very difficult for either of us to perform gentle throttle manipulations at low speed without the car either momentarily hesitating or shooting off like a rocket. Likewise, when slowing down and then resuming posted speeds in situations like slowing for a traffic light transitioning from red to green, there is a similar difficulty predicting what will result from gentle throttle inputs. In other scenarios, the engine is a marvelous and velvety smooth beast.

Back in April 2012, we had the following update performed at Gault BMW in Endicott NY:
“A new software calibration was just released for this engine:
SI B24 02 12
Subject:
N52T/N55 with 8HP45: Delay in Engine Response
Model
F25 with either N52T or N55 engines and 8HP45 transmission up to 1/16/2012
Situation
When slowing down to lower suburban road speeds and then reaccelerating, a delay in engine response may be experienced
Cause
Unfavorable EGS and DME software calibration
Correction
Program the vehicle using ISTA/P 2.46.0 or higher”

In October, we took the car back to Gault BMW. The friendly service staff and technicians could not find any codes and confirmed the SW update was correctly performed back in April. Again, they were very professional and supportive, but were unable to solve the problem. We’ve been Acura customers since the mid-1990’s and decided to give BMW a try last year. There is so much to love about our X3, but this problem is a definite sore spot. We would greatly appreciate if BMW would get to the root cause of this problem.

Sincerely,

zzzzzz"

gfeiner

03-26-2013 12:32 PM

Good to hear. Now only if they would fix the cold start rattle problem.

Teemo Panda

03-26-2013 03:52 PM

Quote:

Originally Posted by gfeiner
(Post 7472843)

Good to hear. Now only if they would fix the cold start rattle problem.

Why is that a bad problem?

gfeiner

03-26-2013 04:43 PM

Quote:

Originally Posted by kamigawa120
(Post 7473438)

Why is that a bad problem?

Until they figure out the cause of the noise, we don't know if it is a sign of something serious. The sound itself is embarrassing. It makes a $50k car sound like $500 junker. It has turned heads when starting up in a parking garage.

Want the Thrill

03-26-2013 04:50 PM

Quote:

Originally Posted by gfeiner
(Post 7473581)

Until they figure out the cause of the noise, we don't know if it is a sign of something serious. The sound itself is embarrassing. It makes a $50k car sound like $500 junker. It has turned heads when starting up in a parking garage.

That doesn't sound normal. Mine does not rattle upon start up. Have you compared yours to other X3's on their lot?

gfeiner

03-26-2013 06:29 PM

Quote:

Originally Posted by Want the Thrill
(Post 7473596)

That doesn't sound normal. Mine does not rattle upon start up. Have you compared yours to other X3's on their lot?

No. But others with the 2012 X3 35i have. It's only cold starts and lasts for 10-15 seconds. It's so brief i havent been able to narrow down the exact loaction of the aound. It's easy to miss if you are not next to a wall or in a garage when you start up cold. Here is the thread:http://www.bimmerfest.com/forums/sho...ght=cold+start

c3uo

03-26-2013 07:40 PM

I have the same noise. It's definitely wastegate rattle.

I'm anxious to see if the SIB fixes the throttle tip-in issue. I can (begrudgingly) live with the wastegate noise at cold start.

csmcphail

04-05-2013 08:44 PM

Still happy with hesitation fix

Approaching two weeks driving since first post and still pleased.

csmcphail

05-16-2013 08:19 PM

6 Weeks, still working!

lbjgh

05-16-2013 08:58 PM

I came close to not buying the x3 after test driving the x3. I loved everything about its performance with the exception of the throttle delay fault. In the end I chose the x3 over other cars and searched for third party fixes for the issue while waiting for delivery. Sprintbooster had a fix for the design fault but fortunately my my2013 had the corrected throttle mapping. [ hope BMW fired someone over that substandard engineering.

Here is a video of the sprintbooster I was going to buy if my car was delivered with the fault,

My wife's X3 was made in April 2012, so it should have the later software. I don't drive it often, but the tip-in delay drives me nuts every time I do. My poor dogs are tired of being tossed around in their crate! I'm definitely going to inquire about this service bulletin when I take it in for the oil service in a few weeks.

lbjgh

08-18-2013 04:29 PM

Many X3 owners 'learn' to drive with the fault but as you pointed out other drivers who are use to proper throttle mapping really find the fault annoying. Let's hope the dealership updates the mapping on your car.

Quote:

Originally Posted by m3bs
(Post 7780955)

Coming in late to this party, but I just found this thread.

My wife's X3 was made in April 2012, so it should have the later software. I don't drive it often, but the tip-in delay drives me nuts every time I do. My poor dogs are tired of being tossed around in their crate! I'm definitely going to inquire about this service bulletin when I take it in for the oil service in a few weeks.